The AKG K812 Professional Reference Headphone

AKG K812 Professional Reference Headphones ($1499)
In 2005 AKG introduced the K701 to much acclaim, and joined the Sennheiser HD600 and Beyerdynamic DT 880 250 Ohm to form the triumvirate of world class dynamic headphones at the time. I prefer the HD600 with its warmer tone, but all three were, and remain, excellent headphones.

In 2009, Sennheiser introduced the HD 800 at $1500 and pushed the price and performance ceiling of dynamic headphones to a new high. In the years since, many new $1000+ headphone have entered the rarified air of ultra-high-end headphones, including: Beyerdynamic T1 ($1399); Audeze LCD2 ($1145), LCD-3 ($1945), and LCD-X ($1699); HiFiMAN HE6 ($1299); and a number of others.

The problem is, none of them are without flaw. To quote Head-Fi member Beagle from this thread:

I have not heard a +$1000 headphone that wasn't a waste of money in the long run. Or put another way, I haven't heard a +$1000 headphone that didn't have a sound that I could pretty much get for way under $1000.

Put another way, SanjiWatuski produced a document looking at measured performance of flagship cans and came to the conclusion the most don't cut the mustard, and headphones like the HiFiMAN HE-5 ($500) represent performance exceeding that of most $1000+ headphones. The title of his document: "The State of Flagships: An Under-engineered Mess"

As the curfuffle at the top raged on, AKG continued to produce a seemingly endless string of K701 variants in the K702, Q701, K702 65th Anniversary Edition, and K712. Personally, I don't have much of a problem with this—the K701 was a competitive headphone and subsequent variants did show incremental improvement. I don't think manufacturers should abandon a good product without good reason. On the other hand, lots of manufacturers were scrambling to place a product in the four-figure price bracket and it seemed AKG wasn't playing along. Lots of AKG fans in the enthusiast world clamored for a new AKG statement headphone. This last November, they got it.

AKG_K812_Photo_CLose

Physical Characteristics
There is a lot to like about the build quality of the AKG K812 headphone.

The K812 is a full-size, open acoustic, circumaural headphone. The overall color scheme is gun-metal gray, black, and satin-finished metal. The main headband arch is two metal bands covered in a somewhat soft synthetic covering, which appear to be very durable. The headband pad is suspended under the two arches, and is leather with a breathable mesh pad. Head size adjustment is accomplished by detented adjustment slides on either side of the headband pad. The adjustments are quite firm and it's not easy to make the size adjustment while the headphones are on your head, but once in place they remain firmly so. Generally I found the headband and pad very comfortable and prefer it to the "rubber band" auto-adjusting of the K701 series.

AKG_K812_Photo_Adjustment

The earpads of the AKG K812 are protein leather over memory foam and are quite unique in shape. The opening of the earpad is actually narrower than the inside of the earcup, which is very spacious—people with large ears will have no problems whatsoever with these headphones. The part of the earpad low and behind the ear has an extra large lip with the words "Sound Sealing" imprinted upon, which intends to provide a better than normal seal in the troublesome spot where skull, neck, and jawline come together in a somewhat unpredictable manner. I found this structure to work very well, and applaud AKG for this novel and practical design.

AKG_K812_Photo_EarPad

The rear of the ear capsules are acoustically open using a perforated plastic mesh on the exterior and a fabric mesh attached inside. These headphones definitely do not isolate you at all from outside noise, but that's by design so no problem there. The driver housing is a short cylinder at the rear of the ear capsules, which is attached to the headband by a gimbal assembly. AKG calls this a "cardanic hinge." Not sure I buy that, Wikipedia defines cardanic hinge essentially as a universal joint; I think the assembly on the K812 is more like a gimbal, but they're quite similar so I won't make a big stink of it. Either way, this design does work very well, properly lining up the earpads with the side of your head effortlessly.

One thing I noticed that I, very surprisingly, didn't see in any of the threads about the K812 was that it appears to use a flexible printed wire assembly (FPWA) to get the signal from the headband conductors to the earpiece and driver. If you look in the photo below you'll see a shiny thing within the red oval, that's the flat printed wire part.

AKG_K812_Photo_FlatWire

I'm not a big believer in swapping cables; I think that as long as there isn't any blatant problem with a cable not much is to be gained with cable swaps. On the other hand, I do think cables can make modest differences, so have no problem with the idea of using quality cable and connections. This little bit of FPWA has me a bit worried though. Is it soldered to its end connections or just pressure fit? Is the cable through the headband normal or FPWA as well?

Since we're on the topic of cables, one thing I find to be a real bummer is that the connector on the left ear piece is only three conductor. This means that it would be very difficult to upgrade the K812 to balanced operation. I know this headphone is meant for professional applications in which this is likely not a problem, but it seems to me the enthusiast market is just as likely to have a desire for this type of headphone and, for them, this is a big problem.

I did do a little looking around and it does seem that there is a way to convert the connectors to four-pin. My best guess is that the Lemo connector on the cable is a FGG.00.303.CLAD35, and what you need is a FGG.00.304.CLAD35. Fortunately, you don't need to change the whole connector, it appears that you can just change the insert for the plug and jack. If you go to this Lemo .pdf catalog, and do a search for "FGG.00.304.YL" you'll find the listing for the insert with the female part right next to it. This is just to get you started if you want to attempt the cable change, I would need to physically check the parts to be certain I've found the right ones.

Also included in the box is a very nice "Omega" style headphone stand. Sadly no carry case is included.

In sum, I found this a very comfortable headphone; styling though somewhat utilitarian remains appealing to my geek eyes. Build quality appears very good, though there have been a few reports of failures, notably three instances of distortion developing in one ear—I'm curious if these failures have been related to the printed wire assemble connections at the earpiece—and one instance of a cracked earpiece. Physically, I like these headphones very much—sonically, it's another story all together, which I'll tell you on the next page.

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COMMENTS
MLegend's picture

Hey Tyll, loved the review and man, what a shocker to find out how dissappointing these cans performed considering the amount of time that have probably gone into making them. Too bad because they are a gorgeous looking pair of headphones imo. Anywho, when you were discussing the trio of the world class dynamic headphones in 2005, You mentioned the Sennheiser HD600 and complimented them for their warm tone. Did you mean the HD650's? I haven't heard either of them but everyone and their dog compliments the 650's for their warm tone and says the 600's are more neutral. Just thought i'd let you know just in case you weren't aware. 

Tyll Hertsens's picture

The HD 600 came out first, so I was comparing the initial three.  Relative to the 701 and 880, the 600 does have a warmer tone.  But yes, the 650 is even warmer than the 600 to my ears.

MLegend's picture

Oh...lol well then my bad. Alright well just making sure man. Thanks again for the review!

Jazz Casual's picture

The K812 is a big deal in the headphone world and warranted this review. So thank you Tyll for deciding to do it despite your initial reluctance. It's informative and even-handed. That's all you can hope for from a professional review, whether it's ultimately favourable or not. 

Tyll Hertsens's picture

It's not something I like to do, but my past experience (with Focal, for instance) is that strong companies (like AKG) will respond in powerful ways given the opportunity. 

Beagle's picture

...constructive criticism can work wonders and help the designers refine their products.

Only problem is that the early adopters lose out, sort of.

Tyll Hertsens's picture

...they call it the "bleeding edge."

Dadracer's picture

The Auralics on loan...........arggggghhh. The Taurus is a brilliant match for the HD800 and I cannot hear any thiness with RLJ even on CD. Ok yes thanks to the Auralic twins I am listening to CDs for pleasure......who knew?

timmyw's picture

I'm really surprised you reviewed these Tyll. I am very interested in what that lovely DAC sounds like though :). 

I really want to audition the Taurus as well but there is no where near where I live that has it.

*sigh*

neo's picture

Are the LCD-X next Tyll?? Also I'm curious about the new Bottlehead Headphone Kit made for the Crack..

Tyll Hertsens's picture

Well, got a couple three posts that will be prior, but current revs of the LCD-X, LCD-3, and LCD-2 are in the house and on and off my head for a review.

AGB's picture

The fact is Tyll, depending on each headphone/amp/wire system, no headphone is flat. Change the ouput impedance of the amp and the can's response changes.

It can become a "chasing one's tail" game. For example, the LCD-3 has a smoother treble and more powerful bass (with my DACs) than the X. For me the X is still preferred. They all need various EQ adjustments and the LCDs are far more forgiving in the highs than other world class cans - they rarely become frazzled. I have no idea why some audiophiles get unhinged about DSP with a Q of 1, do you?

In any event, with my DAC I cut the bass for the LCD-Xes -3dB at 48Hz which flattened out the entire midrange, the lowest octave became more powerful and most importantly, audible; and I boosted the mids and top to open up the soundspacing +3dB @ 1.5K and 1.8dB @ 7K. These are parametric and octave-wide EQs, the two last overlap. I find the bass too much for all of the LCD models. The boost at the top opens the soundstage up, widely, and the transparency (inner details) gain significantly...and with all that the sense of livelyness and dynamics.

These changes are slight be any measure (even good rooms impose far greater FR changes for speakers at the listening seat.)

All I can say and why I am pushing this idea is:

It works. Try it.

The ear is a resonance chamber, each person's is different. We may hear music and the sounds of instruments more or less the same way, but we all hear a different "flat" with the cans attached to and sealing our noggins.

Lastly, resistance is futile! smiley

tony's picture

Seems something is very wrong here : a damaged headphone sample , the Amp is clipping , something a bit loose or a driver overtightened ,  the reviewer and manufacturer should've discussed this Crisis  , the sample problem needs to be located and described .  Who is Editing ? , somebody is dropping the ball here !   I am a Manufacturer that would make every attempt to get out in front of something like this .   

Please let us readers know what happened here , this will make an interesting story , and do try to evaluate with various Amps , a bit more disclosure would be informative , this review seems a bit rushed , not typical of the Great Tyll .       

Tyll Hertsens's picture

I did echange emails with a member of the design team after receiving the first sample of these cans. I heard what I consider the treble problem immediately and after confirming what I heard with measurements I reported my findings to AKG reps. I also posted my measurements on Head-Fi.

During subsequent listening I gained further appreciation of the other stallar aspects of these cans. Response to my measurements ranged from dismay on the part of those who hadn't heard the cans, to disbelief by those who had. A number of reviewers who I respect heard these cans differently than I, so I thought it important to keep my opinion maliable for a while longer. 

There was some additional clammor from enthusiasts thinking I had possibly got a poor sample pair, a possibility which both I and AKG reps also entertained. I requested a second sample. I listened and measured them upon receipt, and found them to be quite similar to the first pair received.

At one point, either in open forums or emails, I forget which, an AKG rep said maybe I should review them anyway as I found them to have strong points along with the problem I perceived. That, along with numerous request by email, PM, and post from enthusiasts finally convinced me to publish my opinion.

So, to your post Tony, I have no amp problems, two samples measured nearly identical so that's the production product in my mind. 

It may be worth mentioning that the Beyer T1 measures very similarly to the K812, and I disqualify it as a flagship can for just about the same reasons. I like the overall sound of the K812 quite a bit better though.

Baconator's picture

I remember reading about your Danish "review or not to review" struggle on that other site. Really glad you went ahead with it.

So to sum up:

HD800- overly bright

T1- poor imaging/terrible treble (depending on which or your reviews one reads)

AKG812- harsh upper mids

Lcd-2 rev 2- recessed treble/small stage

Maybe TOTL won't be the best way for me to go.

At this point I'm looking at the HD600,  HE500 and the Shure 1840 for an open can. All of these are considerably cheaper. The only one you seem not to like out of  these is the Shure. Could you share a comparison to the other two phones based on what you remember hearing? Thanks.

Tyll Hertsens's picture

Sure, I'll play:

I'd say the T1 and K812 problem is similar, low treble not upper mids. The upper mid "ee" sounds harden up in their overtones in the low and mid treble.

The HD 800 just needs a +5dB warm tilt up in the bass and it would be perfect. :)

The current production LCD-2 sounds different to me than previous versions--no comment review coming. 

I think the LCD-3 may be the most pleasureable $1000+ headphone...but it's because I can't afford the Stax 009 and HeadAmp Blue Hawaii.

avens's picture

About the HD800, have you delivered feedback directly to Sennheiser? From what I've read the relatively simple mods and using higher quality cables do wonders, wonders which should be included from the box in their flagship (or call it 850).

 

To be honest I haven't tried that many flagship headphones, for example missing the Stax and the said product, but so far I think the LCD-3 are on a level of their own.

NZtechfreak's picture

Try the HE-6 on a good amp (note that a good amp does not necessarily equate to an expensive amp), for me as an HD800, T1 and LCD2.2 owner I have to say that a well-driven HE-6 nails pretty much everything. If you commit to amping it well then the HE-6 is a bit of a steal at it's price.

Baconator's picture

I really appreciate it! 

My bad though. I was asking about a comparison between the1840, HD600 and HE-500 though. I probably could have phrased the question better.

Sorry but I don't get the "play" reference. I genuinely want to know. <:)

terry's picture

Listening with AURALIiC  and testing with HeadRoom amp, and wondering why measurements do not match listenings ?

tony's picture

Thank you Tyll for responding to my Comments about your review samples of the K812 , maybe AKG's first run of products are duds and they are just trying to sell-thru before moving on , lots of companys will try this kind of thing , sadly .   

I keep watching your writings , anxious to read & watch what you have to discover , especially : the new OPPO cans , the MSB Analog DAC with it's sub-Femto Clock and perhaps a Wall of Fame for Amps.  

Thank you very much for pointing out Jason Stodard's writings and his and Mike Moffat's Products .

You and Steve G at the other site are two super "Reference" Minds concerning all things Personal Music , I know of no other Industry that has one of your quality , much less two , thank you to both of you ,  please pass that on .

Tony 

clohmann's picture

I must say that the K812 review is a bummer but I trust Tyll's opinion. If AKG could only have made two cables (one per driver) easily swappable for aftermarket cables from folks like Moon Audio, etc., they could be greatly improved as is - my guess. I have HD800s and used Moon Audio's recommended Black Dragon cable which made these cans sound so much more musical with much improved treble and a transparent/realistic midrange to trully take advantage of tubed headphone amps.

All in all, I think that will more design tweeks and two cable inputs instead of one will bring the K812s into the sonic realm more befitting of the price!

 

Thanks Tyll for telling it like it is!

MGbert's picture

Tyll:

Bravo for your honest reviews of most of the best known AKG cans.  As luck would have it, the recently released K612 is the one I pulled the trigger on, and find a lot to like at their price point.  Any plans to at least test a pair for measurements, if not a full review?

MGbert

RussellD's picture

I find it surprising that the Beyer T1 has the same problem - I was on the point of asking you whether it did, since you hadn't mentioned them in the review. The lower treble harshness that you mention is a pet peave of mine with so many speakers - especially, as it turns out, those without dedicated midrange drivers because either the bass/mid driver is being asked to go higher than it wants to or the tweeter is being asked to go lower than it wants to and the corrossover range is compromised. I find Diana Krall's voice triggers this distortion - she uses a lot of power in that range and it it sounds brash or harsh - and most speakers can't handle it properly. My K+H 0300s with their 3" dome midrange do, and that's one of the reasons I got them.

I just ordered a pair of Beyerdynamic 1350s based on a few very strong endorsements (and the current blow-out prices!) and I hope they are not similarly afflicted. If they are I'll have to content myself with the fact that the bass range is excellent, apparently. They will still be useful with their carrying case and closed design for remote recording gigs. I currently use Etymotic ER4Ss for this and have for over 15 years, but it would be nice to have a headphone I can hand to a client musician at a recording session.

I don't have a website, but here is a link to some of my recording activities: http://www.6moons.com/industryfeatures/armenia/armenia.html

Cheers, and thanks for your many years of attention to the needs of the headphone user, Tyll. I bought a Headroom Supreme from you back in around 1995 or 96 to drive my Etymotics and am enjoying it still.

Russell Dawkins

AstralStorm's picture

Unfortunately, from my experience with DT1350, they do have a treble problem.
Seems to be a ringy spike around 14 kHz, sounds like grain in many recordings. As it is not just a frequency response bump, equalizing it leaves the grain intact, just subdued.

That and unequalized they do sound like a mess as well, quite a bumpy ride.

You'd be way better off with Sennheiser Momentum if you need a closed headphone. With Sennheiser HD600 or Hifiman HE-400 otherwise.

veggieboy2001's picture

Too bad! I was rooting for the 812's.

We can hope that someone will come up with a simple mod...

Oh well. maybe they'll get it right for the Q812's...

370lbgorilla's picture

I second the notion that you should review the K612.  They are only $219 here in Canada (compared to a staggering $1729 for the K812).  I've even read a few forum comments by listeners stating they actually prefered the sound of the K612 to the K701/K702.

Allen

johnjen's picture

It seems to me that AKG has an 'opportunity' here to 'fix the problems', that is if the old saying of 'it's not a true test of character when things go 'wrong', but what happens next, that matters'.

If this holds true in this case, we may yet see a 'perfected' 812 varient.

I suspect that they will, given their longevity and success thus far.

 

But for me, not being able to run them balanced, is a curious design choice that means I'll never hear these cans on my system.  Mores the pity.

 

JJ

GNagus's picture

I would be more interested to know how the K812 would compare against high-end headphones you dont like; specifically the Grado Labs PS1000 and Ultrasone Edition 10.

Dano91's picture

Thanks Tyll for another interesting review.
You mentioned that Focal Spirit Professional, NAD VISO HP50, HE-500, and HD 600 sounded dull and boring in comparison with high-end. Could this be explained by their more neutral sound than high-end's ? Thanks

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